Datasheet LT3071 (Analog Devices) - 24
| Hersteller | Analog Devices |
| Beschreibung | 5A, Low Noise, Programmable Output, 85mV Dropout Linear Regulator with Analog Margining |
| Seiten / Seite | 30 / 24 — APPLICATIONS INFORMATION. Quieting the Noise. Figure 6. 1.5V to 1.2V … |
| Dateiformat / Größe | PDF / 1.1 Mb |
| Dokumentensprache | Englisch |
APPLICATIONS INFORMATION. Quieting the Noise. Figure 6. 1.5V to 1.2V Linear Regulator
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LT3071
APPLICATIONS INFORMATION Quieting the Noise
capacitor minimizes reference noise to 10µVRMS at the The LT3071 offers numerous noise performance advan- 600mV REF/BYP pin, equivalently a 17µV contribution to tages. Each LDO has several sources of noise. An LDO’s output noise at VOUT = 1V. See the Typical Performance most critical noise source is the reference, followed by Characteristics for Noise vs Output Voltage performance the LDO error amplifier. Traditional low noise regulators as a function of CREF/BYP . buffer the voltage reference out to an external pin (usually This approach also accommodates reference sharing through a large value resistor) to allow for bypassing and between LT3071 regulators that are hooked up in cur- noise reduction of reference noise. The LT3071 deviates rent sharing applications. The REF/BYP filter capacitor from the traditional voltage reference by generating a delays the initial power-up time by a factor of the RC time low voltage VREF from a reference current into an inter- constant. VREF remains active in nap mode, thus start-up nal resistor ≅ 19k. This intermediate impedance node time is significantly reduced and well controlled coming (REF/BYP) facilitates external filtering directly. A 10nF filter out of nap mode (EN:LO↑HI). 50k VBIAS PWRGD 2.2V TO 3.6V 2.2µF BIAS VIN IN 1.5V PWRGD EN 330µF SENSE VOUT V LT3071 O0 OUT 1.2V V 5A O1 2.2µF* 4.7µF* 10µF* VO2 *X5R OR X7R CAPACITORS VMON NC MARGA IMON 2V AT 5A FULL SCALE VIOC REF/BYP 1k 1nF GND 0.01µF 3071 F06
Figure 6. 1.5V to 1.2V Linear Regulator
3071fc 24 For more information www.linear.com/LT3071 Document Outline Features Description Applications Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Applications Information Package Description Revision History Typical Application Related Parts
APPLICATIONS INFORMATION Quieting the Noise
capacitor minimizes reference noise to 10µVRMS at the The LT3071 offers numerous noise performance advan- 600mV REF/BYP pin, equivalently a 17µV contribution to tages. Each LDO has several sources of noise. An LDO’s output noise at VOUT = 1V. See the Typical Performance most critical noise source is the reference, followed by Characteristics for Noise vs Output Voltage performance the LDO error amplifier. Traditional low noise regulators as a function of CREF/BYP . buffer the voltage reference out to an external pin (usually This approach also accommodates reference sharing through a large value resistor) to allow for bypassing and between LT3071 regulators that are hooked up in cur- noise reduction of reference noise. The LT3071 deviates rent sharing applications. The REF/BYP filter capacitor from the traditional voltage reference by generating a delays the initial power-up time by a factor of the RC time low voltage VREF from a reference current into an inter- constant. VREF remains active in nap mode, thus start-up nal resistor ≅ 19k. This intermediate impedance node time is significantly reduced and well controlled coming (REF/BYP) facilitates external filtering directly. A 10nF filter out of nap mode (EN:LO↑HI). 50k VBIAS PWRGD 2.2V TO 3.6V 2.2µF BIAS VIN IN 1.5V PWRGD EN 330µF SENSE VOUT V LT3071 O0 OUT 1.2V V 5A O1 2.2µF* 4.7µF* 10µF* VO2 *X5R OR X7R CAPACITORS VMON NC MARGA IMON 2V AT 5A FULL SCALE VIOC REF/BYP 1k 1nF GND 0.01µF 3071 F06
Figure 6. 1.5V to 1.2V Linear Regulator
3071fc 24 For more information www.linear.com/LT3071 Document Outline Features Description Applications Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Applications Information Package Description Revision History Typical Application Related Parts